And Russia has proven they don’t know how to do logistics and keep their tanks fueled. So a bunch of Tanks without logistics = a losing army.
A big army is really about logistics more than anything. Russia may fix their issues after humiliating defeat. But it will be tough as their culture doesn’t support what is needed to maintain a modern military. So their best bet for now is to focus on Nukes and stop invading other countries.
And your opinion is based on what? Ukrainian propaganda?